<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title></title>
</head>
<body>
欢迎${subject.principal}登录成功！<a href="${pageContext.request.contextPath}/logout">退出</a>
<pre>===============================</pre>
${requestScope}<br>
<pre>===============================</pre>
${requestScope.subject}<br>
<pre>===============================</pre>
${pageContext}<br>
<pre>===============================</pre>
${sessionScope}
<pre>===============================</pre>
"${requestScope.qwe}"
<pre>===============================</pre>
</body>
</html>